Using the slurry reaction sintering process to prepare Hf-Ta-Si composite coating on Ta12W alloy surface,the effect of Si content on the in-situ formation mechanism of the Hf-Ta-Si coating was investigated.Results sho...Using the slurry reaction sintering process to prepare Hf-Ta-Si composite coating on Ta12W alloy surface,the effect of Si content on the in-situ formation mechanism of the Hf-Ta-Si coating was investigated.Results show that 30Hf:70Si coatings exhibit inferior surface uniformity with some pores.The upper part of the sample displays a four-layer gradient structure:the outermost layer is primarily composed of HfSi and HfC,the middle layer consists of(Ta,Hf)_(5)Si_(3)solid solution,the lower main-layer consists of TaSi_(2),and the coating/substrate interface layer is Ta_(5)Si_(3).However,the flow of molten Si under gravity leads to Si-enrichment on the lower part of the coating.After optimizing the Hf:Si ratio to 40:60,the gradient differences in elemental distribution on the coating surface decrease.The surface layer is dominated by HfSi/HfC,but the precipitation of HfC becomes more uniform.The continuity of the(Ta,Hf)_(5)Si_(3)solid solution in middle layer is enhanced,whereas the lower layer and the interface transition layer remain unchanged.Overall,a denser multi-layer gradient structure is formed with improved surface uniformity.Additionally,the acid-alcohol resin in the organic solvent suffers high-temperature pyrolysis and in-situ reacts with Hf to generate the ultra-high-temperature ceramic HfC.This phenomenon is expected to enhance the oxidation resistance and high-temperature stability of coating.展开更多
基金National Natural Science Foundation of China(52071274)Natural Science Foundation of Shaanxi Province of China(2025JC-YBMS-466)+1 种基金Key Research and Development Projects of Shaanxi Province(2023-YBGY-442)Science and Technology Nova Project-Innovative Talent Promotion Program of Shaanxi Province(2020KJXX-062)。
文摘Using the slurry reaction sintering process to prepare Hf-Ta-Si composite coating on Ta12W alloy surface,the effect of Si content on the in-situ formation mechanism of the Hf-Ta-Si coating was investigated.Results show that 30Hf:70Si coatings exhibit inferior surface uniformity with some pores.The upper part of the sample displays a four-layer gradient structure:the outermost layer is primarily composed of HfSi and HfC,the middle layer consists of(Ta,Hf)_(5)Si_(3)solid solution,the lower main-layer consists of TaSi_(2),and the coating/substrate interface layer is Ta_(5)Si_(3).However,the flow of molten Si under gravity leads to Si-enrichment on the lower part of the coating.After optimizing the Hf:Si ratio to 40:60,the gradient differences in elemental distribution on the coating surface decrease.The surface layer is dominated by HfSi/HfC,but the precipitation of HfC becomes more uniform.The continuity of the(Ta,Hf)_(5)Si_(3)solid solution in middle layer is enhanced,whereas the lower layer and the interface transition layer remain unchanged.Overall,a denser multi-layer gradient structure is formed with improved surface uniformity.Additionally,the acid-alcohol resin in the organic solvent suffers high-temperature pyrolysis and in-situ reacts with Hf to generate the ultra-high-temperature ceramic HfC.This phenomenon is expected to enhance the oxidation resistance and high-temperature stability of coating.
文摘随着微电子技术的不断发展,MOSFET 的特征尺寸已缩小至100nm 以下,SiO_2作为栅介质材料已不能满足技术发展的需求,因此必须寻求一种新型高 K 的介质材料来取代 SiO_2。当今普遍认为 Hf 基栅介质材料是最有希望取代 SiO_2而成为下一代 MOSFET 的栅介质材料。综述了高 K 栅介质材料的意义、Hf 基高 K 栅介质材料的最新研究进展和 Hf 基高 K 栅介质材料在克服自身缺陷时使用的一些技术;介绍了一款由 Hf 基高 K 介质材料作为栅绝缘层制作的 MOSFET。
